GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2004-09 > 1096015273


From:
Subject: Re: [DNA] SNP Testing - An R1a Surprise
Date: Fri, 24 Sep 2004 04:41:13 EDT


In a message dated 9/23/04 10:00:03 AM Pacific Daylight Time,
writes:

> I am in communication with a fellow with "our" haplotype. Much to our
> suprise he came back R1a minus, with SNP testing via FTDNA. He was assigned to
> the "R" category (found most frequently in Central Asia). Who knows how many
> others would also find a "surprise" if SNP tested. I maintain, however, that
> he needs to be tested for R1a1 (M17) to rule out a back mutation somewhere
> upstream.

Huh! Did FTDNA test more than one SNP in this case?

Back mutations "should" be extremely rare, as SNPs are treated as Unique
Event Polymorphisms, with a mutation rate of .00000002 per base. The YCC chart
does show a few back mutations and parallel mutations (labeled .1 and .2, or a
and b), but I don't think you can count on a back mutation to salvage your
hypothesis.

Ann Turner - GENEALOGY-DNA List Administrator
Search or Browse the archives, Subscribe or Unsubscribe at
http://lists.rootsweb.com/index/other/DNA/GENEALOGY-DNA.html

This thread: